Related Experiment Video
Updated: Aug 10, 2026

Quantification of Orofacial Phenotypes in Xenopus
Published on: November 6, 2014
True oligodontia with microdontia in monozygous twins: implications for reappraisal of Butler's Field Theory
1Department of Anatomical Sciences, University of the Witwatersrand, Parktown, Johannesburg, RSA.
Abstract:
Oligodontia, which may be defined as the congenital absence of six or more teeth apart from third molars, affects less than 0.5% of the population and may occur in isolation or as part of a syndrome. This paper aims to clarify the role of genetic factors in this condition by reporting a case of a pair of identical twins and their mother who display similar patterns of oligodontia without medical problems. Each twin has 13 missing permanent teeth and their mother 16 missing teeth, but the patterns of agenesis do not conform with Butler's Field Theory according to which the distal teeth in each class are most likely to be absent. Unerupted third molars are present in both twins and all three family members display maxillary lateral incisors. Dental crown size profile patterns were computed for all three individuals and highlight a marked reduction in mesiodistal and buccolingual dimensions of the remaining teeth in each. In addition, erupted teeth showed simplified crown morphology. Oligodontia should not be viewed in isolation, but rather considered as one manifestation of a variety of dental changes in genetically susceptible individuals.
Related Concept Videos
Multiple Allele Traits
Pleiotropy
Genomic Imprinting and Inheritance
The expression of some genes depends on which parent passed the gene to the offspring, through a phenomenon known as...
Incomplete Dominance
Lethal Alleles
Lucien Cuénot discovered lethal alleles in 1905 while studying the inheritance of coat color in mice. The agouti gene is responsible for the color of the coat in mice. This gene codes for an agouti-signaling protein, which is responsible for melanin distribution in mammals. The wild-type allele gives rise to gray-brown coat color in mice, while the mutant allele gives rise to yellow coat color. In addition to coat color, the agouti gene is associated with the yellow...
Teeth
In the bud stage, the tooth germ (an aggregation of cells) starts to form in the developing jawbone. During the cap stage, the tooth germ differentiates into enamel organ, dental papilla, and dental sac, which will later develop into the tooth's enamel, dentin and...

